During the modern era of antibiotic treatment, we have gained unprecedented control over diseases that have plagued humans for centuries. Among the pathogens that the average American never encounters is Mycobacterium leprae, the causative agent of leprosy. This is also known as Hansen’s Disease, named after G.H. Armauer Hansen, who first isolated and described the bacterium in 1873. Thankfully though, while many of us have heard of this now-exotic disease, very few Americans will ever see someone with this condition.

Poster from before the 1979 eradication of smallpox, promoting vaccination. (Photo credit: Wikipedia)

Why is it that members of the public health community are worried about falling vaccination rates in the US when getting vaccinated is treated as a largely personal choice? Do our personal health decisions for ourselves and our children have an impact on the health of society as a whole?

The answer to this is that yes, our individual decisions do matter to society when it comes to combating the spread of contagious disease.

A large part of this is herd or community immunity; the way in which mass immunity in a population can control the spread of disease among individuals. Herd immunity is a major reason behind why so many deadly diseases have all but disappeared from American society; our vaccination rates protect many of those who are unvaccinated from contagious diseases. However, this is beginning to change in the US and we are beginning to see outbreaks of diseases that have not been of major clinical concern for decades.

Syphilis is a bacterial disease caused by the spirocheteTreponema palladium. While this may be something that most of us have (thankfully!) never encountered there have been multiple reports of this disease in the news and a recent resurgence in infection rates around the globe.

During the month of July and August there was a moratorium in the California pornography community due to an outbreak of syphilis that began with one infected performer1 who forged his most recent test results after it returned positive. This actor then went back to work after treatment but while he was still highly contagious; subsequently infecting nine individuals2. Since this outbreak was discovered all involved persons have been treated and the further spread of this disease has been prevented. However, this outbreak this raises two significant questions about syphilis and what it means to be infected:

What exactly is syphilis?

Why is the appearance of syphilis so significant that it required the shutdown of an entire industry?

Much has been in the news lately about the human microbiome and the implications this research has for our health. For those of you not familiar with the term microbiome, it is the sum of all normal, non-pathogenic bacteria that live on and inside our own bodies on a daily basis. These are very large and diverse populations, so much so that bacterial cells outnumber the cells of our own bodies ten-to-one and it is estimated that humans are host to literally thousands of species of bacteria. This doesn’t even begin to cover the number of viruses that may live in us long term; referred to as a virome. It seems today that we are far more complex organisms than we ever imagined. But what does this complexity mean? Does it have implications in how we should treat disease or why we become sick in the first place? Continue reading An ecosystem unto ourselves→

In many ways, our generation is extremely fortunate when observed through the lens of history. Many of us will never know the pain of losing a sibling or child to polio, rheumatic fever, or diphtheria or the worry of minor cuts and scrapes becoming a lethal, untreatable infection. The advances of modern science and medicine have provided us with an arsenal of antibiotics to combat bacterial diseases, as well as effective vaccines that prevent many viral and bacterial infections from taking hold in the first place. However, our widespread abuse of antibiotics in both clinical and agricultural settings has led to an alarming increase in the amount of antibiotic resistant bacteria circulating in the environment and in our own bodies. Continue reading Our depleting antibiotic arsenal→

Necrotizing fasciitis. For many people this is one of the most terrifying, invasive infections imaginable, and for one unlucky woman in Georgia this is her current reality. Reports of this disease date back to Hippocrates in 500 BC, whose early description was that “diffused erysipelas caused by trivial accidents, [where] flesh, sinews, and bones fell away in large quantities, [leading to] death in many cases1.” Many people regard the disease as a medical monster, an invasive and lethal infection that progresses at a rate straight out of science fiction.

For those of you not familiar with the story, a young Masters student named Aimee Copeland was injured while on a home-made zipline. When the line broke she fell and cut her leg on rocks in the river beneath her. What started as a small cut on her leg quickly grew into a life threatening infection that resulted in the amputation of her entire left leg and possibly her hands in order to limit the spread of the disease. How is it possible that a small injury so quickly became life threatening? To understand this we have to understand more about necrotizing fasciitis itself and the bacteria that cause it.